Thursday, June 7, 2012

Start Your Engines!

In my last post, I used the analogy of an engine and fuel tank to explain the concept of body composition, and how one's fat mass should be proportional to one's muscle mass.  In this post, we'll continue using the vehicle example to explain why I feel that strength training is a critical factor in decreasing body fat.
Let's again imagine that in our driveway we have an idling motorcycle that has a gas tank the size of a car.  This model is typical of what the average American looks like (i.e., little muscle & lots of fat).  We sit in our driveways, barely moving, never taxing the engine and burning very little fuel.

One day we decide we want to correct this imbalance, and we vow that we are going to take our bike out of the driveway every day for 20 minutes in order to burn off some of the excess fuel in the tank.  During that 20 minutes of driving, our fuel consumption increases but for the other 23 hours and 40 minutes per day, our bike sits idling in the driveway, burning the same amount of fuel that it did before our ride.  This strategy mimics what we do when we undertake an exercise program that consists only of aerobic activity.  We increase our fat burning during the activity itself, but not during the rest of the day (i.e., when we're "idling").

Now lets say we have a neighbor who also has a bike similar to ours who also wants to get rid of some of his excess fuel.  However, instead of trying to burn the fuel off by driving around the block, he swaps out his little engine for a slightly bigger one.  As his bike sits idling in the driveway, it is now using more of the fuel than it was before, due to the greater size of the engine.  Slowly but surely, the larger engine starts to deplete the fuel in the tank.  If our neighbor decides one day to add an even bigger engine, even more fuel will be burned when the bike is simply sitting idling in the driveway.  This comparison mimics what happens when we use a properly designed weight training program.  As we progressively increase the amount of muscle that we have, so do we increase the amount of fuel that we burn during any given activity.  

While the point of this post is to show the value of weight training, don't trade in your running shoes just yet.  A combination of aerobic activity and strength training is still largely accepted as the optimal way to lose fat.  That being said, I'd personally rather watch a chicken bake than do aerobic exercise, so our next installment will focus on what kind of exercises should be done to maximize muscle gain.   Have a great week!

Miller